In Japan, terrestrial digital broadcasting according to the ISDB-T method has been started from 2003. In every country in the world (Europe, North America, South America, and the Asian bloc) analog broadcasting has been digitized, and ground digital broadcasting is going to be started. In many of the countries, technology which is equivalent to or based on the ISDB-T method in Japan is used. Especially, the OFDM signal that orthogonal multiplexing along a frequency axis has been performed on many carriers is used.
The OFDM signal has the feature strong against a multipass. In order to further improve quality of reception, performing diversity receiving for every carrier multiplexed on the frequency axis is proposed (for example, See Document 1).
In order to perform diversity receiving for every carrier, the diversity receiving apparatus needs to be provided with a plurality of branches.
Depending on an electric wave status, receiving status in any of the plurality of branches may be deteriorated.
Using carriers decoded by a branch in a bad receiving status for performing combination for every carrier in diversity receiving causes deteriorating receiving accuracy by contraries.
Keeping decoding operation of the branch in the bad receiving status as it is causes not only deteriorating the receiving accuracy but also arising unnecessary power consumption.
When the decoding operation of the branch in the bad receiving status is resumed after having stopped the decoding operation, data stored when stopping may cause malfunction of the branch. In this case, it takes extra time to obtain enough receiving accuracy after resuming the decoding operation of the branch.
[Document 1] Japanese Patent Application laid-open on No. 2004-242191